Telegram messaging app CEO and co-founder Pavel Durov in Abu Dhabi, United Arab Emirates, in October. (Giuseppe Cacace/AFP/Getty Images) Russian authorities have opened an investigation into Telegram founder and tech mogul Pavel Durov on suspicion of "abetting terrorist activities," a sign that the widely used messenger app -- deeply embedded in everyday life and a key communications tool for Russian troops in Ukraine -- may soon face an official ban in the country.